Let-off foe



U HE@ @Tf `r opinion.

IVILLIAM H. GRAY, OF DOVER, NEW' HAMPSHIRE LET-OFF FOR LOOIJIS.

Specicaton of Letters Patent No. 31,969, dated April 9, 1861.

To all whom it may concern Be it known that I, IVM. H. GRAY, of Dover,in the county of Stratford and State of New Hampshire, have invented anew and Improved Let-Off for Looms, of which the following is a full,clear, and exact description, reference being had to the accompanyingdrawings, making part of this specification, in which- Figure l is aplan, Fig. 2 an end view, Fig. 3 details of the let off motion detachedfrom the loom.

The delivery of the yarn from the beam is governed entirely by thetension of the warps, and is effected by the return motion of the layindependently of the mechanism which effects the take up, except thatthe latter is effected by the forward beat of the lay.

In the accompanying drawings A are the yarns which proceed from the beamB over the whip roll f to the weaving point; the woven cloth passing inthe usual way over the breast beam to the take up roll C. The latterroll is operated positively by means of a crank C upon the lay shaft C2which crank carries a pawl C3 by the vibrations of which theintermittent rotary motion is communicated to the ratchet wheel C5, thearbor of which carries a pinion C3 which engages with a gear C7 upon thearbor of the take up-roll or cloth beam C. This roll is roughened andthe cloth after passing nearly once around is wound upon the roll C8,the axles ofV which rise in slotted guides in the customary manner asthe cloth upon the roll accumulates. Any return motion of the cloth beamis prevented by the retaining pawl C. The yarn beam B carries at oneextremity a gear B which engages with the worm B2 upon the upright shaftB3 to the bottom extremity of which is secured a circular disk B4immediately above which is an arm B5 which fits snugly though nottightly upon the shaft and works freely around it. From the arm B5 issuspended a curved clamp or jaw B6 which works freely around the pin eas a center. The interior of the jaw B6 is curved to correspond nearlyto the circular exterior of the disk B4, so that it may be moved freelyaround the disk when its ends are left free. The jaw is also so hung ate that if it be held from moving at this point while its oppositeextremity is moved in the direction of the arrow (Fig. 3) the extremeend or nose a of the jaw will bind upon the circumference of the diskB4, and then upon further motion in the samedirection the disk will becarried with the jaw and a rotary motion to a certain extent will beimparted to the shaft B3, which, through the connections alreadyexplained, will turn the yarn beam and let off a certain amount of yarn;the amount `of yarn let off being dependent upon the position of thenose a at the1 moment when it is caused to grip the dis To the innerextremity of the jaw B6 is attached at c a bent rod B7 of the form seenin Fig. 3, which carries an adjustable stop BS, against which one of theswords of the lay strikes upon its return motion and after each beat. Itwill be seen on inspection of Fig. 3 that on the inner end of the jaw B6being thrownback by the blow of the lay upon the stop BS if the jaw beleft free at the opposite extremity a it will simply swing aroundcarrying the arm B5 with it, but that l on the motion of this arm beingchecked any further motion of the jaw in the direction of its arrow willcause it to grip the disk and carry it with it. This gripping of thedisk B4 by the jaw at the exact moment required to give ofi' therequired amount'of yarn after each beat of the lay, is effected in thefollowing manner.

D is a rod which I term the tension indicator and which is of the formseen most clearlyv in Fig. 3. At g it is allowed to turn freely or pivotin bearings secured to the framework, the bent portion D pressing uponthe woven cloth with a force determined by the adjustable weight D2 uponthe arm D3 projecting from the rod. At Di the rod is bent downward andis jointed to a rod D5 the other end of which is jointed to the arm B5.

The operation of this mechanism `is as follows: The weight D2 isadjusted upon its rod D3 so asV to produce the required tension upon thewarps, the cloth is then wound upon the roll C8 until the arm D3 ishorizontal, or this may be effected by turning the shaft B3 by means ofthe hand wheel F. On the lay making its forward beat the cloth is takenup a certain amount and the warps are thereby strained. This turns therod D in its bearings and throws the rod D5 in the direction of itsarrow, which also carries back the arm B5'in the same direction andholds it at the point determined by the llo tension of the warp. On thereturn motion of the lay the eye B9 upon the sword E strikes against thestop B8 and carries the jaw B6 in the direction of its arrow. The

ivot e being held stationary as before explained by the tension of thewarps, the first motion of the jaw B6 causes its nose a to bind againstthe disk Bt whereby the disk is rotated by the further motion of thejaw. For the more perfect operation of the loom, the nose a of the jawmay be kept constantly in contact with the disk by a spring 71 one endof which is attached to the jaw while the other bears upon the arm B5.This I have not found to be necessary in most cases.

It is obvious that the above described mechanism will let ofi an amountof yarn after each beat of the lay exactly equal to the amount which wastaken up by that beat, and that the tension of the warps will always bethe same at the moment when the lay beats up.

In the machine represented in the drawings the arm D4 is connectedpermanently to the rod D5; in practice however there should be anadjustment somewhere between the rod D and the rod D5. Any positive takeup may be employed in place of the one described, and it is evident thatthe form of the parts may be varied without departing from my invention,and the same is also true of the relative position of many of the parts,for instance, it matters not on which side of the cloth the rod D bears,whether front or back, and whether the portion D bends up or downprovidedthe connections between this rod and the let off be suitablyvaried to correspond with this change. The strain mayfeven under certaincircumstances be taken from the warps back of the lay, but this willmanifestly be inferior to the method of taking it from the cloth as thewarps are subjected to the vibration occasioned by the beat of the lay.In practice it is lfound well to put sufcient friction upon the disk B4or upon some other attachment to the shaft B3 to prevent any frivolousmotion of the yarn beam. It is also obvious that the weight D2 may bereplaced by a spring without altering the spirit of my invention.

What I claim as my invention and desire to secure by Letters Patent is-The combination of the balanced rod D, the arm B5, disk B4 and jaw Bb ortheir equivalents for determining the tension under which the loom shalloperate and the amount of let 0E to be effected after each beat of thelay.

WVM. H. GRAY. [Ls] Witnesses M. D. WHITAKER, ALONZO WAIT.

